Search results for "endangered specie"

Spatial analysis of lanner falcon habitat preferences: Implications for agro-ecosystems management at landscape scale and raptor conservation

2014

Abstract Sicily hosts the largest European population of the endangered lanner falcon, a poorly known species which needs conservation planning based on habitat preferences. A distribution model on 10 × 10 km cells of Sicily was described using Generalized Linear Models and variation partitioning methods. This modelling approach extracted explanatory factors, pure and joint effects of greatest influence from subsets of variables controlled for multi-collinearity and spatial autocorrelation. Analytical cartography used the environmental favourability function to assess habitat preferences, and the insecurity index estimated the degree to which lanner falcon occupancy is represented in the Na…

Genetic differentiation and structure of Hippocrepis valentina (Leguminosae) populations

2000

We present an analysis of isozyme variability in natural populations of the plant species Hippocrepis valentina (Leguminosae), which is endemic to the eastern Mediterranean coast of Spain and currently has endangered species status. Our results, obtained by starch-gel electrophoresis of 15 loci, show normal levels of variability for species with similar biology. The comparison with the patterns of genetic variability of two closely related species, H. balearica and H. grosii, confirms the taxonomic status of H. valentina as a proper species, independent of H. balearica, as previously suggested. The analysis of population subdivision shows that substantial variation among populations is pres…

Reproductive biology and conservation implications of three endangered snapdragon species (Antirrhinum, Plantaginaceae)

2009

About 32% of Antirrhinum species are considered to be endangered; however, no field studies have focused on their reproductive biology. In this work, several aspects of the reproductive biology (flowering phenology, floral biology, breeding system) and potential limits on seed quantity and quality (pollen limitation, inbreeding depression) were studied in natural populations of three endangered species of the genus (Antirrhinum charidemi, Antirrhinum subbaeticum, Antirrhinum valentinum). Results disclose that all three species need insect visitors for seed production since fruit set after autonomous self-pollination was lower than under hand cross-pollination. A. charidemi and A. valentinum…

Distribution, ecology and conservation status of Dionysia involucrata Zaprjag., an endangered endemic of Hissar Mts (Tajikistan, Middle Asia)

2014

<em>Dionysia involucrata</em> Zaprjag. (Primulaceae) is known as critically endangered endemic species of Hissar Mountains in Tajikistan. It is reported from few localities mainly in Varzob River valley and its tributaries. The species inhabits steep or overhanging faces of granite rocks in narrow river gorges. During the research all known populations of <em>D. involucrata</em> were examined in respect of the habitat conditions and species composition of vegetation plots. We analyzed the population extent of the species in its range in Tajikistan and the main threats in order to assess its conservation status. The detrended correspondence analysis was performed on a…

Comparative analysis of biological and ecological differentiation of Anemone palmata L. (Ranunculaceae) in the western Mediterranean (France and Spai…

2002

The western Mediterranean geophyte Anemone palmata L. is one of the most endangered angiosperm taxa in France. The biological and ecological characteristics of French populations are contrasted with those of populations from near the centre of the species distribution in east Spain. A Correspondence Analysis discriminates the French and Spanish populations according to substrate and the composition of the plant communities where they grow. The karyological study reveals that east Spanish plants are autotetraploid, whilst the French are all diploid. In addition, morphological differences were registered, Spanish plants generally being more vigorous. French populations consist mostly of senil…

Habitat Preferences for Territory Selection by the Endangered Eastern Iberian Reed BuntingEmberiza Schoeniclus witherbyi

2014

Summary. Given the 80% decline of the eastern Iberian reed bunting Emberiza schoeniclus witherbyi breeding population in recent decades, our aim was to identify the habitat components selected during territory establishment and to characterise the vegetation features that are positively or negatively selected at the territory scale. GLMM were used to explain the occurrence of territories in 11 wetlands. Fourteen variables with four vegetation dominance categories were analysed with respect to habitat composition, while occupancy of seven vegetation classes and 12 reed structural parameters were analysed with respect to habitat structure. The proportion of reed-cattails (Typha) measured by t…

Abies nebrodensis, Silene hicesiae

2017

Veronico beccabungae-callitrichetum stagnalis (Oberd. 1957) Müller 1962, a plant association new to Poland - Quality of habitat

2011

The paper presents a community of water plants that is new to Poland, <em>Veronico beccabungae-Callitrichetum</em> stagnalis (Oberd. 1957) Müller 1962. This community belongs to the class <em>Potametea</em>. It was discovered in the village of Odrowąż near the town of Krapkowice in Silesia (SW Poland). <em>Veronico beccabungae-Callitrichetum stagnalis</em> in Poland occurs within an irregularly shaped shallow underwater spring, located in the distal part of the Oder River’s flood terrace. This plant community covered 0.2 ha in 2008. <em>Callitriche stagnalis</em> predominated in this community. Species such as <em>Callitriche hamulata&lt…

Habitat preference of endangered Eastern Iberian Reed BuntingsEmberiza schoeniclus witherbyi

2011

Capsule Careful management is required to maintain or create habitats with the correct proportions of rush with reeds that are preferred by this subspecies. Aims To determine the habitat requirements of Eastern Iberian (Western Iberian Reed Buntings were not included in the study) Reed Buntings Emberiza schoeniclus witherbyi, a subspecies endemic to a few marshes in France, Spain and Morocco, with a population of 254–360 breeding pairs. Methods Twenty-five wetlands in Spain were surveyed and presence/absence of Iberian Reed Buntings was deteremined together with data on 41 environmental variables. The relationships between the birds and habitat data were investigated using glm. Results Prop…

Ecological variation between marginal and central populations of Potamogeton polygonifolius, a rare and endangered species in Central Europe

2012

Abstract The present study is focused on Potamogeton polygonifolius – the species considered to be endangered in Germany, the Czech Republic, Poland and Switzerland. Field studies were carried out in Lower Silesia and Lusatia in southwestern Poland in order to verify the present state of the marginal populations of P. polygonifolius, to determine the habitat preferences of the species in the study area, to compare the ecological data between marginal and central populations and finally to recognise the factors constraining the easternmost limit of the P. polygonifolius. In total, 18 populations were examined, and 11 releves were collected. The releves gathered were compared with 95 releves …